2022-03-22 Meeting Meeting Notes

 Date

Mar 22, 2022

 Participants

• @Jonathan Cameron

• @Lorenzo Pieralisi (Deactivated)

• shameerali.kolothum.thodi@huawei.com

• ed@amperecomputing.com

• Ilkka Koskinen <ilkka@os.amperecomputing.com>

• @Joyce Qi

 Goals

• Welcome Edg and Ikka from Amperecomputing to join the discussion for more discussion.

• Two main topics discussed:

  • vCPU Hotplug Update

    Current status

    • ACPI spec change via code first route approved.

    • Kernel patches being reworked / rebased by ARM. Expected to be sent

     out in 5.19 cycle.

    • QEMU patches being updated by Huawei.  Will do at least some light testing

     and then push out a public git tree so that others can test - will aim
     to do this so it aligns with kernel code availability.

    • Ed (Ampere) gave an update to say they are interested in pushing this

     forwards ASAP and have customer / OS vendor engagement which will be
     very useful in moving towards a complete solution, particularly ensuring
     good test coverage etc.

    Noted that current QEMU patches may not cover all corner cases, for example
    live migration of VMs that have vCPUs hotplugged.  Might 'just work'
    but we haven't tested it yet so probably not.

    Given we didn't really add anything on DOE / SPDM over previous calls,
    I don't plan to send out anything on that topic this time.

  • IORT RMR
    discussion:

    • Patchset requiring a final review from ARM (upcoming) but should

     be ready to be merged

    • Handling of IO port access at 0x0 on !x86 to be fixed (caused by UEFI

     allocating addresses starting at 0x0 for BARs and IORT RMR requiring
     the OS to preserve the BAR value) in Linux but it does not affect the
     upstreaming of patches (since the only platform where the issue
     triggers does not have upstream IORT RMR tables)

    • ACPICA pull request still not merged but on its way

    • Targeting v5.19 kernel (probably via ACPI tree to avoid Linux ACPICA

     dependencies)

    • Repost of final version at v5.18-rc1

• Recordings link:

  • Video Conferencing, Web Conferencing, Webinars, Screen Sharing  password：E#%s807u

 Discussion topics

 Action items

• Next time the meeting may be adjusted if US friends will join.

•  

 Decisions